Device and Method for Vascular Access

ABSTRACT

A new device and method are introduced herein to facilitate vascular access in general and the placement of central venous access devices in particular. In one embodiment, the device consists of the following components: a wireless ultrasound imaging handheld scanner, a Bluetooth ECG (electrocardiography) data acquisition module with patient ECG cable and sterile adaptor, and a mobile medical application running on a mobile platform (device), e.g., a tablet, smartphone or smart watch. Ultrasound imaging and/or ECG-based catheter guidance provided by the device disclosed herein can be used to independently or simultaneously visualize the catheter in the vasculature and/or guide its placement at the desired location. In another embodiment of the present invention, ultrasound imaging of the blood vessel targeted for vascular access can be used for assessing the blood vessel size prior to cannulating the blood vessel, for guiding an access needle into the targeted blood vessel, and for visualizing the catheter in the vasculature after the introduction of the catheter. In another embodiment of the present invention, ECG-based navigation of an intravascular catheter can be used for tracking such intravascular catheter in the vasculature and positioning such intravascular catheter at a desired location. In one aspect of the present invention, the ultrasound imaging handheld scanner contains all the electronics required to acquire and process ultrasound images and to transfer them wirelessly to a mobile platform device, e.g., a tablet or a smartphone. In another aspect of the present invention, the ECG data acquisition module contains all the electronics required to acquire and process tracking and positioning information for ECG-based catheter guidance and to transfer such information wirelessly to a mobile platform device, e.g., a tablet or a smartphone. In another aspect of the present invention, algorithms are introduced for processing and synchronization of ultrasound images and ECG signals. In another aspect of the present invention, user interfaces for the handheld ultrasound imaging scanner, the ECG data acquisition module, and the mobile medical application running on a mobile platform are introduced in order to simplify the use of ultrasound imaging and/or ECG-based guidance for catheter placement on mobile platforms. In another aspect of the present invention, a new vascular access method is introduced using simultaneous ultrasound imaging and ECG-based catheter guidance. According to the present invention, using ultrasound imaging of a catheter in the vasculature simultaneously with detecting ECG signals at the tip of the catheter provide accurate and reliable catheter location information in adult and pediatric population for most of patients conditions and clinical environments.

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/104,895 filed on Jan. 19, 2015, the disclosure of which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to the field of vascular access, in particular tothe placement of vascular access devices, e.g., peripherally andcentrally inserted central catheters, implantable ports, etc. Currently,ultrasound imaging is used to guide venipuncture and the insertion of acatheter in a vein and ECG-based guidance is used to confirm the tiplocation of the catheter at the cavo-atrial junction. Electromagnetictracking, Doppler and ECG are used to track (navigate) the intravascularcatheter from the insertion point towards the cavo-atrial junction andchest X-rays, ECG, and fluoroscopy are used to place the catheter tip atthe cavo-atrial junction. Transcutaneous ultrasound imaging is currentlyused to visualize the catheter in the vasculature after insertion and tocheck if the catheter has accidentally moved to an undesired locationwherever ultrasound imaging is available at that location.Transesophageal ultrasound imaging can also be used to accurately placethe catheter tip at the cavo-atrial junction. The purpose of the presentinvention is to provide a single easy-to-use, wireless device whichcombines ultrasound imaging and ECG-based tracking in order to guide aneedle and a catheter for vascular access and to help position thecatheter at the desired location in the vasculature.

BACKGROUND OF THE INVENTION Clinical Need

Vascular access is an important element of any minimally invasiveclinical procedure and of clinical procedures needing access to thecentral venous system, e.g., chemotherapy, parenteral nutrition, etc.The access of the patient's vasculatures involves gaining access to thevasculature through an insertion or access point, inserting a catheterinto the vasculature (cannulation) and advancing the catheter throughthe vasculature to the desired end location of the catheter tip. Indifferent clinical situations the desired location of the catheter tipmay be different for each of the situations. Due to the patient'sanatomy, the catheter may not always go the desired route in thevasculature from the insertion to the end point. In many clinicalsituations accessing the patient's veins or arteries at the desiredaccess point may be challenging because of the patient's anatomy orbecause of the blood vessel size and patency. For these reasons, devicesand methods are needed to guide the insertion of a catheter into a bloodvessel, the navigation of the catheter through the vasculature on thedesired path, and the placement of the catheter at the desire location.

PRIOR ART

Currently, ultrasound imaging is used to guide venipuncture and theinsertion of a catheter in a vein and ECG-based guidance is used toconfirm the tip location of the catheter at the cavo-atrial junction.Electromagnetic tracking, Doppler, ECG, and fluoroscopy are used totrack (navigate) the intravascular catheter from the insertion pointtowards the cavo-atrial junction and chest X-rays, fluoroscopy, and ECGare used to place the catheter tip at the cavo-atrial junction. Further,transcutaneous ultrasound imaging is currently used to visualize thecatheter in the vasculature after insertion and to check if the catheterhas accidentally to an undesired location wherever ultrasound imaging isavailable at that location. Transesophageal ultrasound imaging can alsobe used to accurately place the catheter tip at the cavo-atrialjunction.

Contributions of the Present Invention

The purpose of the present invention is to provide a single easy-to-use,wireless device which combines ultrasound imaging and ECG-based trackingin order to guide a needle and a catheter for vascular access and tohelp position the catheter at the desired location in the vasculature.

SUMMARY OF THE INVENTION

A new device and method are introduced herein to facilitate vascularaccess in general and the placement of central venous access devices inparticular. In one embodiment, the device consists of the followingcomponents: a wireless ultrasound imaging handheld scanner, a BluetoothECG (electrocardiography) data acquisition module with patient ECG cableand sterile adaptor, and a mobile medical application running on amobile platform (device), e.g., a tablet, smartphone or smart watch.Ultrasound imaging and/or ECG-based catheter guidance provided by thedevice disclosed herein can be used to independently or simultaneouslyvisualize the catheter in the vasculature and/or guide its placement atthe desired location.

In another embodiment of the present invention, ultrasound imaging ofthe blood vessel targeted for vascular access can be used for assessingthe blood vessel size prior to cannulating the blood vessel, for guidingan access needle into the targeted blood vessel, and for visualizing thecatheter in the vasculature after the introduction of the catheter.

In another embodiment of the present invention, ECG-based navigation ofan intravascular catheter can be used for tracking such intravascularcatheter in the vasculature and positioning such intravascular catheterat a desired location.

In one aspect of the present invention, the ultrasound imaging handheldscanner contains all the electronics required to acquire and processultrasound images and to transfer them wirelessly to a mobile platformdevice, e.g., a tablet or a smartphone.

In another aspect of the present invention, the ECG data acquisitionmodule contains all the electronics required to acquire and processtracking and positioning information for ECG-based catheter guidance andto transfer such information wirelessly to a mobile platform device,e.g., a tablet or a smartphone.

In another aspect of the present invention, algorithms are introducedfor processing and synchronization of ultrasound images and ECG signals.

In another aspect of the present invention, user interfaces for thehandheld ultrasound imaging scanner, the ECG data acquisition module,and the mobile medical application running on a mobile platform areintroduced in order to simplify the use of ultrasound imaging and/orECG-based guidance for catheter placement on mobile platforms.

In another aspect of the present invention, a new vascular access methodis introduced using simultaneous ultrasound imaging and ECG-basedcatheter guidance. According to the present invention, using ultrasoundimaging of a catheter in the vasculature simultaneously with detectingECG signals at the tip of the catheter provide accurate and reliablecatheter location information in adult and pediatric population for mostof patients conditions and clinical environments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Overview of the device and method for vascular access accordingto the present invention

FIG. 2: Wireless hand held ultrasound imaging device according to thepresent invention

FIG. 3: Method of use of the ultrasound imaging device according to thepresent invention

FIG. 4: Needle guide for the ultrasound imaging device according to thepresent invention

FIG. 5: Block diagram of the ultrasound imaging device according to thepresent invention

FIG. 6: ECG device according to the present invention

FIG. 7: Block diagram of the ECG device according to the presentinvention

FIG. 8: User interface for ultrasound imaging according to the presentinvention

FIG. 9: User interface for the ECG device according to the presentinvention

FIG. 10: Block diagram of the software application for the ECG deviceaccording to the present invention

FIG. 11: Block diagram of the software application for ultrasoundimaging according to the present invention

FIG. 12: User interface for patient information input according to thepresent invention

FIG. 13: User interface for ECG device settings according to the presentinvention

FIG. 14: Block diagram of the software application for the vascularaccess device according to the present invention

FIG. 15: User interface for the vascular access device according to thepresent invention

FIG. 16: User interface for ultrasound imaging settings according to thepresent invention

FIG. 17: Method for guiding the placement of catheters according to thepresent invention

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates the device and the method for vascular accessaccording to the present invention. The patient 100 is subject to avascular access procedure, whereby the catheter 140 is inserted in thevasculature, e.g., in the venous system at the access point 141. Thecatheter 140 is pushed such that the catheter tip 134 navigates from theaccess point 140 towards a desired location in the vasculature, e.g., atthe cavo-atrial junction (CAJ) 108 near the sino-atrial node 118 of thepatient's heart 105. On the way towards the cavo-atrial junction, thecatheter tip reaches the subclavian vein 112 and the superior vena cava107 and can inadvertently reach the internal jugular vein 110, the rightatrium 119 or the inferior vena cava 114. The catheter 140 is insertedinto the vein through a needle, which punctures the vein at theinsertion point 141, and which is removed after the insertion of thecatheter.

The hand held ultrasound imaging device 170 is used during the vascularaccess procedure in order to:

-   a) Assess blood vessel size and select the appropriate catheter size    of approximately ⅓ of the blood vessel size.-   b) Verify blood vessel patency to see if there are potential    obstacles along the catheter path-   c) Guide the insertion of the needle into the right blood vessel and    avoid injuring nerves or other relevant tissue.-   d) Verify if the catheter is on the desired path or has reached an    undesired location wherever such path and/or location can be    visualized by ultrasound imaging.

The ultrasound imaging device 170 has an ergonomic hand-held enclosureand communicates wirelessly with the mobile platform device 190 througha wireless communication channel 186 and 196. The housing of the handheld imaging scanner 170 has a flat and wide surface 184 in order toallow for placing the housing on a flat surface, e.g., on a table. Thewireless ultrasound imaging device 170 further comprises a lineartransducer array 171 to transmit and receive ultrasound energy. A pairof buttons on the housing allows for the increase 177 and the decrease176 of the field of view of the ultrasound image. The button 179 allowsfor stopping and starting ultrasound imaging in order to conserve power.The button 180 allows for switching between the ultrasound imaging mode,the ECG-based navigation mode and the combined ultrasoundimaging—ECG-based navigation mode of the device 190. A mechanical needleguide 172 can be mounted on the housing of the device 170 in order toallow for accurate guidance of a needle 174 in the field of view of thetransducer array 171. The cover 182 can be opened in order to allow forthe exchange of rechargeable batteries. The LEDs 183 indicate: a) thestatus of the wireless connection, the battery status, and the on/offimaging status of the device 170.

The Bluetooth ECG data acquisition device 125 provides ECG signals fromthe patient's body and from the tip of the catheter to the device 190via the Bluetooth communication channel 164-191. The ECG signals areacquired by the device 125 from the patient via three leads: a referencelead 130 placed on the patient's abdomen right below the diaphragm 116,a control lead 132 placed on the patient's skin over the jugular notch102, and catheter lead via the sterile adaptor (connector) 144. Theconnector 144 can be an alligator clip which is connected to a stylet orto a guidewire inserted in the catheter 140. The connector 144 can alsobe a saline solution adaptor which makes an electrical connection tosaline solution flowing from a syringe 146 through the catheter hub 142to the catheter tip 134. Using the connector 144, the device 125 canobtain ECG information from the tip 134 of the catheter 140. The LEDs150 indicate: the status of the Bluetooth communication, the batterystatus, and the on/off status of the device 125. The ON/OFF button 152is used to switch the device 125 on and off. Buttons 154 and 156 areused to increase and respectively decrease the scale on the display ofthe device 190 and/or the amplification of the ECG signal in the device125. The button 162 is used to create a reference ECG waveform on thedisplay of the device 190. The button 160 is used to save and printpatient information and ECG waveforms in the memory of the device 190and on an optional Bluetooth printer connected to the device 190,respectively.

The device 190 is a mobile platform, e.g., a tablet or a smartphonewhich runs a mobile application described in the present invention. Onthe display of the device 190 ultrasound images 192 and ECG waveforms193 are displayed according to the present invention. Control buttons194 are used to control the device 190 and to remotely control theultrasound imaging device 170 and the ECG data acquisition device 125.Ultrasound images, ECG waveforms, other patient information and voicecan be transferred via the wireless communication channel 197 to othermobile devices in real time.

FIG. 2 illustrates the wireless hand held ultrasound imaging device 200according to the present invention. The ultrasound imaging device 200consists of an ergonomic housing 230 which allows for the user to easilyhold the housing in one hand and to perform all hand movements necessaryfor ultrasound imaging required by vascular access and needle puncture.A linear transducer array and the associated electronics are used toprovide ultrasound images of appropriate resolution, penetration depth(field of view), and frame rate. Several buttons on the housing 230allow an operator to access the most frequently used functions duringultrasound imaging with only one hand: decrease field of view (208)(shallower) and increase field of view (206) (deeper), switch betweenECG-based guidance, combined ultrasound-ECG guidance, and ultrasoundonly operating modes (210) and starting and stopping ultrasound imagingin order to conserve power (212). The cover 220 can be opened in orderto allow for the exchange of rechargeable batteries. The LEDs 222indicate: a) the status of the wireless connection, the battery status,and the on/off imaging status of the device.

FIG. 3 illustrates a method of use of the ultrasound imaging deviceaccording to the present invention. The ultrasound imaging device 300 isplaced in a stable position with the flat surface of the housing 305 ona flat surface like a table or a cart or other flat surfaces 310 andwith the transducer array 315 facing up. In this position of the scanner300, a single sterile operator can place a sterile bag 320 over thehousing 300 and handle the scanner in such a way as not to compromisethe sterile field while using the scanner 300 and operating its buttons330.

FIG. 4 illustrates a needle guide for the ultrasound imaging deviceaccording to the present invention. The hand held scanner according tothe present invention 400 can be fitted with a device 410 on either sideor laterally in order to allow for guiding a needle 420 in the field ofview of the transducer array 430 in-plane or out of plane. A sterileneedle guide 410 can also be attached to the housing 400 after a sterilebag has been placed over the housing as described in FIG. 3.

FIG. 5 illustrates a block diagram of the ultrasound imaging deviceaccording to the present invention. The linear transducer array of 16 to256 transducer elements 502 is powered by the high voltage generator510. The transmit-receive switch 506 alternates between powering thetransducer array 502 using the high voltage generator 510 during thetransmit time and receiving the incoming signals generated by theincoming ultrasound echoes during receive time. The incoming signalsgenerated by the incoming ultrasound echoes is processed by thebeamformer 514 to form a focused ultrasound beam out of the 16 to 256individual signals generated by the transducer array 502. The highvoltage generator 510, the transmit-receive switch 506 and thebeamformer 514 are synchronized, set up, and controlled by the controlunit 520.

The image processing block 530 generates a raw ultrasound image out ofthe individual ultrasound beams provided by the beamformer 514 andprocesses the received individual beams and the raw ultrasound image inorder to improve signal-to-noise ratio, contrast, and gain, and toreduce image speckles amongst others. The image processed by the imageprocessing block 530 is then transferred to the scan converter 534,which performs linear or bi-linear weighted interpolation and convertsthe image into a format that can be visualized on a display.

The same processed image is also transferred to a feature extractionblock 550 which extracts certain useful relevant features form the imagewhich can serve for automatic control and adjustments of systemsettings. One such extracted relevant feature is the computed differencebetween subsequent images. In the case that such differences betweensubsequent images are not relevant for a certain period of time, it isassumed that the device is not in clinical use and the high voltagegenerator will automatically be turned off by the control unit 520 inorder to conserver battery power.

Other extracted relevant features are the average, the minimum and themaximum amplitudes in an image or in a certain area of an image. Thesefeatures and their changes in time allow for performing automaticadjustment of the signal gain in order to optimize overall gaincompensation and image contrast.

Another extracted relevant feature is the offset or the delay from theimage origin to the first returning ultrasound echo. This offset (delay)is used to compute typical initial internal ultrasound echoes in thetransducer housing and to the patient skin. These initial echoes arevery strong and are eliminated from the image display in order to notinfluence the display of the weaker ultrasound echoes coming from realtargets in the patient's body. This offset (delay) is also used tocompute the reference position for the image display in order tooptimize the presentation of the useful ultrasound image on the displayand not to waste display space for unwanted ultrasound echoes or delays.

The image scan converted by 534 is compressed (lossy or lossless) by thedata compression module 544 in order to decrease the data throughputthrough the WiFi communication channel 560. The image processed by theblock 530 can alternatively be sent to the data compression block 544 inthe case that no scan converting of the image is needed to be performedin the hand held device 170. The data compression module 544 canalternatively be set to no compression, i.e., it does not perform anycompression on the ultrasound images.

The ultrasound images scan converted or not and compressed oruncompressed, as well as the features extracted by the featureextraction module 550 are transmitted by the WiFi communication module560 in real time to the display and receiving device 190 in FIG. 1. Theextracted features by module 550 are also sent to the control unit 520for automatic adaptive adjustments.

The WiFi communication module 560 also receives commands and messagesfrom the device 190 in FIG. 1. These commands and messages areinterpreted and directed to the control unit 520 for execution. The handheld device 170 in FIG. 1 has an user interface consisting of severalbuttons. The inputs from these buttons are processed by the userinterface module 540 and directed to the control unit 520 for execution.The control unit 520 also controls the battery charger 528 and transmitsstatus information about the status of the battery and of the hand-helddevice to the device 190 in FIG. 1 through the WiFi communicationchannel 560.

The temperature sensor 570 measures the internal temperature in thehousing of the hand held ultrasound imaging device. The control unittransmits this value over the WiFi communication channel 560 and takesappropriate power management measures to keep the internal temperatureunder the designated threshold, e.g., by turning off the high voltagegenerator or the battery charger 528. The battery charger 528 chargesthe internal battery 524 which provides power for all the electronics ofthe device including for the high voltage generator 510.

FIG. 6 illustrates an ECG device according to the present invention. Thedevice 600 is an ECG data acquisition and processing device with awireless Bluetooth connection to the device 190 in FIG. 1. The device600 has several connectors for connecting ECG leads: the connector andlead 610 can be connected to a control electrode, e.g., 132 in FIG. 1,the connector and the lead 612 can be connected to a referenceelectrode, e.g., 130 in FIG. 1, the connector and lead 614 can beconnected to catheter, e.g., 144 in FIG. 1, the connectors and the lead616 can be connected to an active, noise-reduction electrode.

The LED 622 indicates the status of the Bluetooth connection, the LED620 indicates if the device 600 is on or off, the LED 624 indicates theinternal battery status. The button 628 is used to turn on and off thedevice 600. Pressing the button 630 sends a “Print/Save” command to thedevice 190 in FIG. 1. Pressing the button 632 sends a “Freeze” commandto the device 190 in FIG. 1. Pressing the button 634 sends a command toincrease the scale of the ECG signal to the device 190 in FIG. 1.Pressing the button 636 sends a command to decrease the scale of the ECGsignal to the device 190 in FIG. 1.

The LED 640 is on when the device 600 is charging. The micro USBconnector 642 allows for charging the rechargeable battery of the device600 via an USB cable. The device 600 transmits ECG and statusinformation to the device 190 in FIG. 1 via Bluetooth. ECG informationincludes raw ECG data, processed signals, and relevant featuresextracted from the ECG signal.

The communication protocol over the Bluetooth communication channelbetween the device 600 and the device 190 in FIG. 1 is structured as toallow the bidirectional transmission of multiple ECG signals, relevantfeatures, and messages in real time. Each signal can be sampled andtransmitted with up to 1000 samples per second per signal The Bluetoothcommunication channel of the device 600 can also receive messages,commands, and settings from the device 190 in FIG. 1.

FIG. 7 illustrates a block diagram of the ECG device according to thepresent invention. ECG signals 702 as described for example by 610, 612,and 614 in FIG. 6 are input to the input optically isolated amplifier704 which are then analog-to-digitally converted by the A/D converter706. The digital signals are processed by the signal processing module730.

The signal processing performed by module 730 includes notch filteringof unwanted frequencies, high pass filtering for base line fluctuationsreduction, common mode rejection and averaging. The signal processingperformed by module 730 further includes synchronization between severalECG signals and the computation of signals using weighted averages ofthe input raw ECG signals.

The feature extraction block 750 detects the R peaks of the ECGwaveforms, marks the location of the ECG R-peak on the ECG signal andcomputes the heart rate using instantaneous and averaged computations.The feature extraction block 750 further detects ECG lead-offconditions, i.e., the conditions in which a lead is not connected to thepatient. The signal processing results and the extracted relevantfeatures of the signals are transmitted over the Bluetooth communicationchannel to the device 190 in FIG. 1 using the Bluetooth module 760.

The Bluetooth module 760 also receives messages from the device 190 inFIG. 1 and transmits commands to the control unit 720. The control unit720 also receives commands directly from the buttons situated on thehousing of device as illustrated in FIG. 6, buttons 630, 632, 634, 636.The control unit 720 controls the status of the LEDs 620, 622 and 624illustrated in FIG. 6.

The control unit 720 also controls the status and settings of thebattery charger 712, of the A/D converter 706, of the signal processingblock 730 and of the feature extraction block 750. The battery charger712 charges the internal battery 710.

FIG. 8 illustrates a user interface for ultrasound imaging according tothe present invention. The user interface 800 is displayed on thetouchscreen 802 of the device 190 in FIG. 1. Display window 804 is usedto display ultrasound images received from the device 170 in FIG. 1. Thedepth scale 806 shows target mm markers and can be used to assess thesizes of objects visualized on the ultrasound images and their distancefrom the face of the transducer linear array.

The field of view indicator 808 is a number indicating the maximum depth(distance from transducer face) which can be visualized at the currentsystem settings. The field of view value can be changed by touching thescreen over the display window 804 of the ultrasound image and by movingthe finger up and down on the touch screen. Moving the finger updecreases the field of view and moving the finger down increases thefield of view. Moving the finger up while touching the screen has thesame effect of decreasing the field of view as pressing the button 208in FIG. 2. Moving the finger down while touching the screen has the sameeffect of increasing the field of view as pressing the button 206 inFIG. 2.

Tapping on the display window 804 when the ultrasound image is displayedin real time freezes the ultrasound image and tapping on the displaywindow 804 when the ultrasound image is frozen unfreezes the ultrasoundimage and switches back to the real-time display mode. A frozen imagecan be displayed in a small window on the bottom of the display 804 forreference purposes.

The touch button 812 is used to start the measurements mode. Touchingthe button 812 while in the measurements mode exits the measurementsmode. The measurements mode can be used to assess the size of theobjects visualized on the ultrasound image. When in measurements mode,when taping a first time on the display window 804, a first marker isdrawn at the tapping location. When tapping a second time on the displaywindow 804, a second marker is drawn at the tapping location, a dottedline is drawn between the two markers and the distance in mm between thetwo markers is displayed close to the dotted line or in one of thecorners of the display window 804. In order to move the location of onemarker, the user has to drag and drop it to a new location by using afinger and touching the touch screen. A new dotted line is drawn and thenew distance is calculated and displayed after the marker was dropped ata new location.

The buttons 810 provide real-time control for ultrasound imaging.Touching the button 812 when in measurements mode, erases all graphicsrelated to measurements and exits the measurement mode. Touching thebutton 814 switches the display mode to a combined displayed mode, inwhich ultrasound images and ECG signals are displayed at the same timeon the display 802 as illustrated in FIG. 15.

Turning the device 800 with 90 degrees in either direction (840)switches the display mode from ultrasound imaging (in portraitorientation) to the ECG mode and display (in landscape orientation) asillustrated in FIG. 9. If an ECG mode and display are not available, theaction switches the ultrasound imaging display from a portrait mode to alandscape mode.

The buttons 815 and 816 are used to change the overall gain setting ofthe ultrasound image: touching the button 815 increases the overall gainand touching the button 816 decreases the overall gain of the ultrasoundimage.

Touching the button 819 enters a “Tools” menu as illustrated in FIG. 16.The field 830 of the graphical user interface provides general controlsand additional functions for the ultrasound imaging device 170 in FIG.1.

The button 832 is divided into a left and a right button. The leftbutton 832 provides a “Home” function, i.e., the mobile device 190 inFIG. 1 goes to its home page without exiting the ultrasound imagingapplication described by the user interface 800. The right button 832provides a “Back” function, i.e., when touching this button, the menunavigation goes one step back to a previous state.

Button 834 switches the display 802 to a “Patient” display illustratedin FIG. 12. Touching the button 836 switches to the Setting menu anduser interface illustrated in FIG. 16. The display window 838 shows thebattery levels of the batteries of the devices 170 and 190 from FIG. 1.

FIG. 9 illustrates a user interface for the ECG device according to thepresent invention. The graphical user interface 900 is displayed on thetouchscreen display of the device 190 in FIG. 1. The display window 902displays a reference (frozen) ECG waveform 910 with a marker marking theR-peak of the ECG waveform. Display window 904 displays a real-timesignal 960, which can be an ECG waveform or a computed signal. TheR-peak of the ECG waveform or a certain location in the computed signalis marked with a marker similar to the marker 912. Display window 906displays a real time ECG waveform from a skin (surface, control) ECGelectrode.

The ECG signals displayed in windows 904 and 906 are acquired and/orcomputed by the device 125 in FIG. 1 and transmitted to the device 190in FIG. 1 over the Bluetooth communication channel 164-191 in FIG. 1.The signal scale of the signal displayed in display windows 904 can beincreased or decreased using two-finger zoom over the touchscreen in thedisplay area 904 to zoom out (increase signal scale) or zoom in(decrease signal scale).

When tapping once on the display window 904 the signal in the displaywindow 904 is copied and frozen as a reference signal in the displaywindow 902. When tapping on the display window 902, the reference signal910 is erased. The baseline of the signal 960 can be moved up and downin the display window 904 by touching the display window 904 anddragging up and down the ECG signal. The baseline of the signal 962 canbe moved up and down in the display window 906 by touching the displaywindow 906 and dragging up and down the ECG signal. The indicator 920indicates the battery level of device 125 in FIG. 1 and the indicator922 indicates the battery level of device 190 in FIG. 1.

Touching the button 926 switches to the patient information screenillustrated in FIG. 12. Touching button 930 prints the waveformdisplayed in window 902 together with patient information input asdescried in FIG. 12 on a Bluetooth printer connected to the device 190in FIG. 1 as described in FIG. 13. Touching the button 930 also savesthe printed image as an image file in jpg format in the memory (internalor removable) of the device 190 in FIG. 1. Touching the button 930 alsosaves the ECG waveforms for a patient in a file in the memory (internalor removable) of the device 190 in FIG. 1. The file names containingprinted images or case data are automatically generated. Touching thebutton 934 switches the graphical user interface to the displayillustrated in FIG. 13.

If an ultrasound imaging device 170 in FIG. 1 is connected to the device190 in FIG. 1, touching the button 938 or rotating the device 190 inFIG. 1 with 90 degrees from landscape to portrait view switches the userinterface to the one illustrated in FIG. 8. The field 940 displays theheart rate computed by device 125 in FIG. 1 and transmitted in real timeto the device 190 in FIG. 1.

Field 944 shows the logo of the device and also serves as start/pausebutton for the real time display of the ECG waveform in display window904. The button 970 provides a “Home” function, i.e., the mobile device190 in FIG. 1 goes to its home page without exiting the ultrasoundimaging application described by the user interface 900. The button 974provides a “Back” function, i.e., when touching this button, the menunavigation goes one step back to a previous state. The button 978 is ashortcut to Settings screen illustrated in FIG. 13.

FIG. 10 illustrates a block diagram of the software application 1000 forthe ECG device according to the present invention. The softwareapplication 1000 can run on any mobile platform fulfilling minimumrequirements, e.g., tablets, smartphones, smart watches and other smartwearable and head-mounted technology. The application 1000 is built on areal-time multi-tasking operating system 1015 and structured intoseveral threads of execution with appropriate execution priorities andcomputing and memory resources.

The Bluetooth communication thread 1010 ensures the communication overthe Bluetooth communication channel 164-191 in FIG. 1 between thedevices 125 and 190 in FIG. 1 and between the device 190 in FIG. 1 and aconnected Bluetooth printer. Upon user request, the “Print” thread 1020prints ECG waveforms and patient information on a Bluetooth printer,when such a printer is connected to the device 190 in FIG. 1. The“Print” thread 1020 also saves data files to the storage mediumavailable in the device 190 in FIG. 1. The “Print” thread 1020 performsthe functions described in FIG. 9 for button 930. The “Print” thread1020 continuously saves in real-time the data received from the device125 in FIG. 1 in a memory buffer.

Upon touching the button 930 in FIG. 9, the data from the internalmemory buffer is converted into an optimized file format and alsotransferred to a permanent storage medium. The thread “Help” 1025 isresponsible for all real-time and off-line activities related toproviding real time context dependent, educational, and on line help tothe user.

The user can obtain real time context dependent help regarding thesystem functionality by touching a question mark drawn on the userinterface, dragging and dropping it on the region of interest on thegraphical user interface, about which the user wants to obtain help.

Educational help is provided in the form of pictures, text, and movieswhich the user can select from a list of available choices.

On line help can be obtained by connecting to available remote helptools, e.g., clinical information database.

Additionally, the user can obtain help using the phone or the wirelesscommunication capabilities of the mobile platform device 190 in FIG. 1.The user can dial a number and can share in real time the informationdisplayed on the graphical user interface, for example on the display inFIG. 9, with the person answering the phone call.

The thread “Settings” 1030 is responsible for activities related tosetting and maintaining the system status, including setting andmarinating the status of devices 125 and 190 in FIG. 1 throughappropriate communication.

The thread “ECG” 1040 is responsible for maintaining the Bluetoothcommunication and for receiving and transmitting messages from and tothe device 125 in FIG. 1, for displaying signals and information,including relevant features on the display of device 190 in FIG. 1 asillustrated in FIG. 9 and for the user interface interaction related tothe display illustrated and described in FIG. 9.

The thread “Patient” 1050 is responsible for implementing the activitiesrelated to the “Patient” button 926 in FIG. 9. A user interfacecorresponding to thread 1050 is illustrated in FIG. 12.

The “Playback” thread 1060 is responsible for activities related toplaying back patient data saved to file. When a case data file is openedusing the “Open Img” thread 1070, the thread “Playback” 1060 reads thecontents of the file and post processes it as if the data was real timedata. I.e., the data can be modified through the user interface as it isdisplayed on the display illustrated in FIG. 9 using all real timecontrols as if the data was real time data. For example, the user canchange the signal scale using a finger zoom function over the display904, modify the baseline of the signals by touching, dragging anddropping the signals, freezing the signal in display window 902, ormodifying the signal scale of the signal displayed in display window906. The thread “Open Img” 1070 is responsible for activities related tofinding and opening a saved file. A file can be saved either as an imagefile containing the printout of the information printed to a Bluetoothprinter or as a case data file containing the signals and informationfor a patient received from the device 125 in FIG. 1.

FIG. 11 illustrates a block diagram of the software application 1100 forultrasound imaging according to the present invention. The softwareapplication 1100 can run on any mobile platform fulfilling minimumrequirements, e.g., tablets, smartphones, smart watches and other smartwearable and head-mounted technology. The application 1100 is built on areal-time multi-tasking operating system 1105 and structured intoseveral threads of execution with appropriate execution priorities andcomputing and memory resources.

The wireless communication thread 1110 ensures wireless communicationover the communication channel 186-196 in FIG. 1 between the devices 170and 190 in FIG. 1 and between the device 190 in FIG. 1 and a Bluetoothor other wireless printer connected to the device 190 in FIG. 1. Inanother embodiment of the present invention, the thread 1110 can ensurereal-time communication with other wireless devices and the real-timebroadcasting over the communication channel 197 of the ultrasound imagesreceived from the device 170 in FIG. 1.

The “Measurements” thread 1115 is responsible for activities related tomeasurements of object on the ultrasound image as described in FIG. 8.

The thread “Help” 1120 is responsible for all real-time and off-lineactivities related to providing real time context dependent,educational, and on line help to the user. The user can obtain real timecontext dependent help regarding the system functionality by touching aquestion mark drawn on the user interface, dragging and dropping it onthe region of interest on the graphical user interface, about which theuser wants to obtain help.

Educational help is provided in the form of pictures, text, and movieswhich the user can select from a list of available choices.

On line help can be obtained by connecting to available remote helptools, e.g., clinical information database.

Additionally, the user can obtain help using the phone or the wirelesscommunication capabilities of the mobile platform device 190 in FIG. 1.The user can dial a number and can share in real time the informationdisplayed on the graphical user interface, for example on the display inFIG. 9, with the person answering the phone call.

The thread “Patient” 1125 is responsible for implementing the activitiesrelated to the “Patient” button 834 in FIG. 8. A user interfacecorresponding to thread 1125 is illustrated in FIG. 12.

The thread “Settings” 1130 is responsible for activities related tosetting and maintaining the system status, including setting andmaintaining the status of devices 170 and 190 in FIG. 1 throughappropriate communication.

The thread “Data Compression” 1135 performs data decompression on theultrasound imaging data received from device 170 in FIG. 1, if thedevice was set to performed data compression as described in FIG. 5.

The thread “Scan Converter” 1140 performs scan conversion operations onthe ultrasound imaging data received from device 170 in FIG. 1 if thedevice 170 does not perform such scan conversion operations. A scanconversion operation is defined as a conversion between the datastructures of ultrasound images as acquired by the beamformer 514 inFIG. 5 and the data structures of the corresponding ultrasound images asdisplayed on the display 804 in FIG. 8.

The thread “Feature Extraction” extracts relevant features from theultrasound image received from the device 170 in FIG. 1. Such relevantfeatures may include averages, gray scale distributions, recognition ofactive the field of view, recognition of idle states of the device 170in FIG. 1, the computation of the image attenuation as a function ofimaging depth, and the recognition of the boundaries and of thecharacteristics of certain objects in the ultrasound image.

The thread “Image processing” 1150 is responsible for imagestabilization and enhancement, e.g., low pass, high pass, band pass andselective filtering, time gain compensation, rescaling, andreorientation of ultrasound images.

The thread “Beamformer” 1155 is responsible for setting and controllingthe module beamformer 514 in FIG. 5. Such setting and controllinginclude selecting beamforming tables computed by thread 1160, settingthe field of view, the amplification scale, and the power management ofthe device 170 in FIG. 1 determined by thread 1165 as a function ofoverall system settings and imaging parameters. Such setting andcontrolling may result from user input or automatically fromcomputations by the threads 1135, 1140, 1145, or 1150 and aretransmitted to the device 170 in FIG. 1 over the wireless communicationchannel 196-186 in FIG. 1.

FIG. 12 illustrates a user interface for patient information inputaccording to the present invention. The display window 1205 displays areal-time ECG waveform from the control electrode 132 in FIG. 1connected to the patient's skin. The heart rate displayed in field 1265in real time is computed by the device 125 in FIG. 1 based on the ECGwaveform acquired from the control electrode 132 in FIG. 1.

The field 1240 displays an alphanumeric keyboard which can be used bytouching the touchscreen of the device 190 in FIG. 1. The softalphanumeric keyboard 1240 is automatically displayed if any of theinput fields 1210, 1215, 1200, 1225 or 1230 are touched. The field 1200labeled “Notes” is a general text input field. The field 1215 is labeled“Device Type” and the user can input information about the vascularaccess device (VAD) used in the clinical procedure. The field 1210 islabeled “Patient” and the user can input the name and/or the ID of thepatient undergoing the vascular access device placement procedure. Thefield 1230 is labeled “Institution” and the user can input the name ofthe clinical institution and/or the name of the clinician performing theVAD placement procedure. Field 1225 is labeled “Inserted Length” and theuser can input the insertion length of the VAD at the end of the VADplacement procedure.

The information input in the alphanumeric fields is stored in thepatient's file and printed on paper on the Bluetooth printer, if such aprinter is connected, when the user touches the button 930 in FIG. 9.Touching the button 1250 opens a dialog box and a display windowallowing the user to select for visualization archived images or toselect a file to playback archived patient data.

The button 1255 switches the screen to the “Settings” displayillustrated in FIG. 13. The button 1260 is labeled “New Patient”. Whentouching this button, all input fields of the display 1200 are clearedand the memory used for temporary storage of patient information andcase data is reinitialized. Field 1270 shows the logo of the device.

FIG. 13 illustrates a user interface for ECG device settings 1300according to the present invention. The display window 1305 displays anECG waveform of the patient from the electrodes connected to the skin asa control electrode. The heart rate displayed in field 1310 in real timeis computed based on the ECG waveform displayed in display window 1305.Field 1315 shows the logo of the device.

Touching the button 1320 switches the display to a display windowallowing for setting up a Bluetooth printer. Touching the button 1325switches the display to the display illustrated in FIG. 12. The displaywindow 1330 displays messages related to the Bluetooth communicationbetween the devices 190 and 125 in FIG. 1 and between the device 190 inFIG. 1 and a Bluetooth printer. The display window 1330 also displaysmessages related to the wireless communication between the devices 190and 170 in FIG. 1, if a device 170 is connected. The display window 1335lists all discovered Bluetooth devices including the device 125 in FIG.1 and a Bluetooth printer and allows for the selection of desireddevices. The button 1340 is labeled “Refresh”. Touching this buttonrestarts the discovery of Bluetooth devices displayed in window 1335.The button 1345 is labeled “Connect”.

Touching the button 1345 allows for establishing Bluetooth communicationbetween the device 190 in FIG. 1 and the device selected in window 1335,i.e., a particular device 125 in FIG. 1. One or more devices 125 in FIG.1 can be discovered but only one such device can be connected at any onetime.

The drop-down selection box 1350 is labeled “ECG rate” and allows forthe selection of the rate for the A/D sampling of the ECG signalsperformed by device 125 in FIG. 1. The drop-down selection box 1355 islabeled “IV Gain” and allows for the selection of the acquisitionamplification and/or display scale of the intravascular ECG signalacquired by device 125 in FIG. 1. The drop-down selection box 1360 islabeled “CE Gain” and allows for the selection of the acquisitionamplification and/or display scale of the ECG control signal acquired bydevice 125 in FIG. 1. The drop-down selection box 1365 allows for theselection of a notch filter implemented by the device 125 in FIG. 1. Theparameters selected using the selection boxes 1350, 1355, 1360, and 1365are sent by the device 190 to the device 125 in FIG. 1 upon selectionover the Bluetooth communication channel 191-164.

Touching the button 1380 labeled “SW Version” displays the version ofthe mobile application running on the device 190 in FIG. 1 and of thefirmware of devices 125 and 170 in FIG. 1.

The drop-down selection box 1385 allows for the selection of the displayscale and/or attenuation coefficient for the ECG control signaldisplayed in window 1305. The signal attenuation for display purposes isperformed by the application running on the device 190 in FIG. 1 and bythe thread 1040 shown in in FIG. 10. Touching the button 1390 resets thesettings of the devices 125, 170, and 190 in FIG. 1 to factory defaults.

The check box 1370 is labeled “R-Peak”. The user can check and uncheckthe box 1370 by touching it. When checked, the device 125 in FIG. 1computes the location of the R-peak in the ECG waveform and the device190 in FIG. 1 displays a marker over the R-peak of the ECG waveform onthe display illustrated in FIG. 9. The user can check and uncheck thebox 1375 by touching it. When checked, the device 125 in FIG. 1 computesanother specific signal related to the tip of the catheter of thevascular access device and the device 190 in FIG. 1 displays this signalin the display window 904 illustrated in FIG. 9.

FIG. 14 illustrates a block diagram of the software application for thevascular access device according to the present invention. The softwareapplication 1400 runs on the device 190 in FIG. 1 on top of a real-timemultitasking operating system 1405. The software module 1410 ensuresBluetooth communication with the device 125 over the communicationchannel 191-164 in FIG. 1 and with a Bluetooth printer. Software module1415 ensures wireless communication over a wireless channel using awireless protocol between the devices 190 and 170 over the communicationchannel 196-186 in FIG. 1. Software module 1415 further ensures wirelesscommunication over a wireless channel using a wireless protocol betweenthe device 190 and another wireless device for the purpose ofbroadcasting in real time patient information, signals and imagesacquired from the patient by the device according to the presentinvention.

In another embodiment of the present invention, the software module 1415also includes capabilities to transfer patient information, signals andimages in real time to another device over a wireless phone and/orsmartphone connection.

The ECG application module 1425 has the functions and the block diagramillustrated in FIG. 10. The ultrasound imaging application module 1430has the functions and the block diagram illustrated in FIG. 11. Thesynchronization module 1440 performs synchronization between the ECGapplication 1425 and the ultrasound imaging application 1430. Thesynchronization performed by the module 1440 includes synchronizationbetween the resources of the device 190 in FIG. 1 allocated to the twoapplications 1425 and 1430, timing synchronization between applications1425 and 1430.

One method of timing synchronization according to the present inventionis ECG-triggered ultrasound imaging and information processing. In suchECG-triggered timing synchronization, the ECG signals and the ultrasoundimages are processed based on a trigger in the ECG waveform, for examplebased on the occurrence of an R-peak in the control ECG signal. Whensuch a trigger occurs, certain parameters of the ultrasound imagereceived from the device 170 in FIG. 1 and certain parameters of thesignals received from device 125 in FIG. 1 are computed by theinformation processing block 1420.

Examples of such computed parameters include blood vessel sizes. Sincethe blood vessel diameter changes during the heart cycle, determiningthe blood vessel size at the same moment in time in each heart cycleleads to a more accurate determination of the vessel size. Thedetermination of the blood vessel size triggered by ECG can be computedor determined with user interaction through the user interfaceillustrated in FIG. 15. Accurate estimation of blood vessel size isimportant for the determination of the size of the vascular accessdevice catheter.

Another type of synchronization and processing performed by modules 1440and 1420 is the correlation of the ultrasound image with the ECG signalat the tip of the catheter at certain locations in the vasculature, forexample in the internal jugular vein. The user interface module 1435 iscontrolling the user interface illustrated in FIGS. 8, 9, 12, 13, 15,and 16.

The user interface module 1435 together with the synchronization module1440 are responsible for switching between the ultrasound imaginginterface illustrated in FIG. 8 and the ECG interface illustrated inFIG. 9 when the device 190 in FIG. 1 rotated by 90 degrees as explainedin FIGS. 8 (840) and 9 (950).

FIG. 15 illustrates a user interface for the vascular access deviceaccording to the present invention. The graphical user interface 1500 isdisplayed on the touch screen of a mobile device 190 in FIG. 1, e.g., atablet or a smartphone. A simplified version of this interface can bedisplayed on a smart watch or on head mounted device. The display window1510 display ultrasound images acquired and processed by the device 170in FIG. 1 and transmitted to device 190 in FIG. 1 over a wirelesscommunication channel.

An ultrasound image 1570 is presented on the display window 1510 withthe origin of the image 1570 on the top of the screen and with thedeepest field of view of the image on the bottom of the image 1570. Thedisplay scale in mm 1515 is displayed to the right of the display window1510. Objects closer to the skin 1575 are displayed closer to the originof the ultrasound image 1570, i.e., closer to the top of the image 1570.Deeper objects 1580 are displayed closer to the bottom of the image1570. The devices 170 and 190 in FIG. 1 ensure good enough resolutionand contrast in order to clearly depict in the ultrasound image 1570veins (1575), arteries (1580) and catheters of at least 3 Fr in size1585 positioned inside blood vessels 1575.

The devices 170 and 190, as well as the communication channel 196-186 inFIG. 1 ensures communication speed and data throughput high enough inorder to display real time ultrasound images at minimum 10 images persecond. The display window 1520 displays the field of view, i.e., themaximum target depth for which ultrasound images can be acquired for aspecific setting of the device 170 in FIG. 1. The display window 1510for ultrasound images ensures the user interface functionality describedin FIG. 8 for the display window 804.

The display window 1560 displays ECG and other signals 1565 acquired andprocessed by the device 125 in FIG. 1 and transmitted to the device 190in FIG. 1 over a Bluetooth communication channel (164-191 in FIG. 1).The display window 1560 ensures the user interface functionalitydescribed in FIG. 9 for display window 904. Touching the button 1540switches the display and the graphical user interface to the userinterface described in FIG. 16. Touching the button 1545 enablesprinting to a wireless printer. Depending on the system settings, eitherthe ultrasound image 1570 or the signal 1565 or both can be printed onone or two different printers. For example, the ultrasound image 1570can be printed on wireless printer using Direct WiFi and the signal 1565can be printed on a Bluetooth printer.

Touching the button 1545 also enables saving of patient information, ECGsignals and frozen ultrasound images in dedicated files on the selectedstorage medium of the device 190 in FIG. 1. Touching the button 1550switches the user interface of the device 190 in FIG. 1 to the userinterface presented in FIG. 8. Touching the button 1555 switches theuser interface of the device 190 in FIG. 1 to the user interfacepresented in FIG. 9.

Buttons 1590 and 1594 provide a “Home” and a “Back” functionrespectively, as described in FIG. 9, buttons 970 and 974 respectively.The field 1530 displays the heart rate computed by the device 125 inFIG. 1. The field 1535 displays the logo of the device. The field 1535also serves as a toggle button for the selection of the signal 1565displayed in display window 1560. One out of two or more signalsacquired and/or computed by the device 125 in FIG. 1 can be selected tobe displayed in window 1560. The button 1525 is a toggle button.Touching the button 1525 enables or disables synchronization functionbetween the ECG signal and the ultrasound image as described in FIG. 14.

FIG. 16 illustrates a user interface for ultrasound imaging settings andtools according to the present invention. The display window 1600 isdisplayed on the screen of the device 190 in FIG. 1 and is divided intoa “Settings” section 1605 and a “Tools” Section 1660. The setting called“Compression” 1610 allows for the selection of the compression ratio forthe ultrasound images transferred from the device 170 to the device 190over the communication channel 196-186 in FIG. 1 through a drop downselection box. When the compression is set to off, ultrasound images aretransferred uncompressed.

Touching the button 1636 toggles on and off the ECG trigger 1614. Whenturned on, the ECG trigger works as described in FIG. 14. The settingTGC curve 1618 allows for the selection of a time-gain compensation(TGC) curve used to optimized image quality by compensating ultrasoundattenuation due to depth. The TGC can be switched off, in which case theblocks 530 in FIG. 5 and 1150 in FIG. 11 do not perform any attenuationcompensation on the ultrasound image. One TGC curve can be selected outof a set of predefined TGC curves by using the drop box 1634. Thepredefined set of TGC curves allows for choosing the optimal ultrasoundattenuation compensation in a typical clinical situation, e.g., whenworking on neonates, when placing peripherally inserted central lines(PICC), when placing implantable ports, when accessing the blood vesselsby femoral access.

The “Scan Converter” setting 1620 allows for turning on and off with thehelp of the selection button 1638 the scan converter function performedby block 534 in FIG. 5. When the scan converter function performed byblock 534 in FIG. 5 is turned off, then automatically the scan converterfunction 1140 in FIG. 11 is turned on and reciprocally, such that onlyone scan converter function is active at one time.

The WiFi select field 1624 displays a list of available WiFi devices inthe display window 1630. By touching the appropriate name listed indisplay window 1630, the device 170 can be wirelessly connected, e.g.,through a direct wireless connection to the device 190 in FIG. 1. TheButton Configuration field 1628 allows the user to configure the buttons1640 of device 170 in FIG. 1 to perform functions selected from the dropdown list 1642. The user touches one of the buttons 1640 to select itand the selects the desired function for that button from the drop downlist 1642. Touching the selected button again allocated the selectedfunction to that button.

The “Tools” menu displayed in display window 1660 allows for performingcertain less frequently used functions. Touching the button “Save” 1665saves patient case data to a file on the storage medium of the device190 in FIG. 1. Touching the button “Play” 1670 allows for selecting astored patient file and playing it back on a display window forultrasound images on the device 190 in FIG. 1. Touching the “Print”button 1675 allows for printing an ultrasound image includingmeasurements to a connected wireless printer. Touching the “Diag” buttonbrings up a number of diagnostics options used to verify thefunctionality of the devices 170 and 190 in FIG. 1. Buttons 1690 and1692 provide a “Home” and a “Back” function respectively, as describedin FIG. 9, buttons 970 and 974 respectively. Display window 1694indicates the battery level of device 170 in FIG. 1 and display window1696 indicates the battery level of device 190 in FIG. 1.

FIG. 17 illustrates a method for vascular access according to thepresent invention consisting of the steps described herein below. Thedisplays illustrated by 1700, 1710, 1720, 1730, 1740, 1750, and 1760 aresimplified forms of the display illustrated and described in FIG. 15displayed on the device 190 in FIG. 1. The ultrasound images illustratedin FIG. 17 are acquired by the device 170 in FIG. 1 and transmitted tothe device 190 in FIG. 1 according to the present invention. The ECGsignals illustrated in FIG. 17 are acquired by the device 125 in FIG. 1and transmitted to the device 190 in FIG. 1 according to the presentinvention. The method for vascular access according to the presentinvention consists of the following steps:

1. Estimation of the blood vessel size considered for vascular accessillustrated by the display 1700. The targeted blood vessel for vascularaccess 1702 is visualized on the ultrasound image in FIG. 15. The skin(surface, control) ECG signal 1708 is selected to be displayed asdescribed in FIG. 15. In order to increase measurement accuracy on theultrasound image, ECG-triggered ultrasound imaging described in FIG. 14is enabled by using the button 1525 in FIG. 15. The blood vesseldiameter 1704 is measured as described in FIG. 8 and displayed in thefield 1706. Thus, the user can estimate the size of the vascular accessdevice which is recommended to be approximately one third of the bloodvessel diameter. The patency of the targeted blood vessel is alsoevaluated at this step using ultrasound imaging along the blood vesseland visualizing differences in the blood vessel diameter along the bloodvessel. The diameter of the blood vessel may decrease due toobstructions such as blood clots, tumors, or other causes. In general,the size of the access device catheter should be one third of theminimum diameter of the targeted blood vessel on the desired catheterpath.

2. Puncture and access of the targeted blood vessel illustrated by thedisplay 1710. In display 1710 an uncompressible artery 1716 and acompressible vein 1714 are illustrated, displayed by ultrasound imagingin case of peripheral access. In the ultrasound image, the access needle1712 is also illustrated. The access needle can be inserted in thetargeted blood vessel under ultrasound guidance freehanded or by usingthe needle guide described in FIG. 4. The skin (surface, control) ECGsignal 1718 displayed simultaneously with the ultrasound image is usedto monitor the patient's heart rate and the presence of any heart rhythmabnormalities, e.g., extra systoles. The heart rate and heart rhythmabnormalities are computed using the detection of the R-peak 1719 of theECG waveform as described in FIG. 9 and displayed in the field 1530 inFIG. 15.

3. Checking the catheter path within the blood vessels illustrated bythe display 1720. Wherever accessible to ultrasound imaging, thetargeted blood vessel path for the catheter placement is visualized, forexample in a longitudinal view 1722. If the catheter 1724 is in thetargeted blood vessel, the catheter can be visualized on the ultrasoundimage, as well as the catheter tip 1726. An ECG signal 1728 is displayedsimultaneously with the ultrasound image. A skin (surface, control) ECGsignal is selected for the display 1728 and used to monitor thepatient's heart rate and the presence of any heart rhythm abnormalities,e.g., extra systoles, for example when the catheter touches the wall ofthe right atrium. The heart rate and rhythm abnormalities are computedusing the detection of the R-peak 1729 of the ECG waveform as describedin FIG. 9 and displayed in the field 1530 in FIG. 15. An intravascularECG signal at the tip of the catheter is selected for the display 1728and used to correlate in real time the position of the tip of thecatheter 1726 visualized on the ultrasound image with the ECG waveformfrom the tip of the catheter at that location. Checking the catheterpath within the blood vessels illustrated by the display 1720 can beperformed either by longitudinal ultrasound imaging, i.e., along a bloodvessel or by transversal ultrasound imaging, i.e., perpendicular on ablood vessel.

4. Checking abnormal catheter locations as illustrated in Figure 1730.If the catheter did not follow the desired path through the vasculatureand could not be visualized in step 2, abnormal positions of thecatheter within the vasculature are checked as illustrated by 1730.Wherever accessible to ultrasound imaging, the possible abnormalcatheter locations, e.g., in the internal jugular vein are visualized. Acatheter 1734 can be identified in a blood vessel in a transversal view1732. Checking the catheter path within the blood vessels illustrated bythe display 1730 can be performed either by longitudinal ultrasoundimaging, i.e., along a blood vessel or by transversal ultrasoundimaging, i.e., perpendicular on a blood vessel. A skin (surface,control) ECG signal is selected for the display 1736 and used to monitorthe patient's heart rate and the presence of any heart rhythmabnormalities, e.g., extra systoles, for example when the cathetertouches the wall of the right atrium. The heart rate is computed usingthe detection of the R-peak 1738 of the ECG waveform as described inFIG. 9 and displayed in the field 1530 in FIG. 15. An intravascular ECGsignal at the tip of the catheter is alternatively selected for thedisplay 1736 and used to correlate in real time the position of the tipof the catheter visualized on the ultrasound image 1734 with the ECGwaveform from the tip of the catheter at that location. Checking thecatheter path within the blood vessels illustrated by the display 1730can be performed either by longitudinal ultrasound imaging, i.e., alonga blood vessel or by transversal ultrasound imaging, i.e., perpendicularon a blood vessel.

5. Approaching the cavo-atrial junction as illustrated in 1740. Asdescribed in the literature, as the catheter tip of the vascular accessdevice approaches the cavo-atrial junction the P-wave 1744 of the ECGwaveform 1742 increases. The P-wave can be easily identified as beingthe predominant waveform to the left of the R-peak 1748 of the QRScomplex 1746 of the ECG-waveform 1742.

6. In order to place the catheter tip at the cavo-atrial junction, thecatheter is first advanced beyond the cavo-atrial junction until theP-wave of the ECG waveform 1755 situated to the left of the marker 1758indicating the peak of the R-wave 1759 starts to decrease or becomesbiphasic with a negative first peak 1756 and a predominant secondpositive peak 1757. Then, the catheter is pulled back to the cavo-atrialjunction until the P-wave 1752 situated to the left of the marker 1754of the R-peak of the R-wave 1753 of the ECG waveform 1751 reaches itsmaximum positive amplitude without presenting the biphasic aspectidentified by 1756 and 1757.

7. The ultrasound image showing a blood vessel of interest 1761 and thecatheter 1762 inside that vessel, as well as the ECG waveform 1764corresponding to the catheter tip location at the target location arefrozen on display 1760 and saved to the patient file using the userinterface described in FIG. 15. The information is printed wirelessly(1770) to a wireless printer 1780 for documentation purposes.

What is claimed is:
 1. A method for vascular access, the methodcomprising: obtaining an ultrasound image of a blood vessel, obtainingan ECG signal from a skin electrode, obtaining an ECG signal from thetip of a vascular devices in the said blood vessel, analyzing the saidultrasound image and the said ECG signals, and providing informationhelpful to vascular access in real time as a result of said analysis. 2.The method as defined in claim 1, wherein acquisition of the ultrasoundimages is synchronized with the ECG signal obtained from the skinelectrode.
 3. The method as defined in claim 2, wherein thesynchronization of the ultrasound image acquisition with the ECG signalis used for a more accurate assessment of the blood vessel size in viewof vascular access.
 4. The method as defined in claim 2, wherein thesynchronization of the ultrasound image acquisition with the ECG signalis used for a more accurate assessment of the blood vessel patency inview of vascular access.
 5. The method as defined in claim 1, whereinthe ultrasound image of a vascular device in a blood vessel is displayedsimultaneously with the ECG signal at the tip of the vascular device onthe same display.
 6. The method as defined in claim 5, wherein thelocation of the catheter tip in the blood vessel is estimated based onthe correlation between the ultrasound image and the ECG signal.
 7. Adevice for vascular access, the device comprising: an ultrasound imageacquisition and processing unit an ECG signal acquisition and processingunit a display and graphical user interface unit
 8. The device asdefined in claim 7, wherein the ultrasound image acquisition andprocessing unit comprises a module to perform ultrasound imageacquisition and processing on a trigger.
 9. The device as defined inclaim 7, wherein the ultrasound image acquisition and processing unitcomprises software to perform data compression.
 10. The device asdefined in claim 7, wherein the ultrasound image acquisition andprocessing unit comprises software to perform pattern recognition. 11.The device as defined in claim 7, wherein the ultrasound imageacquisition and processing unit comprises software to perform scanconversion.
 12. The device as defined in claim 7, wherein the ultrasoundimage acquisition and processing unit comprises software to perform timegain compensation.
 13. The device as defined in claim 7, wherein theultrasound image acquisition and processing unit comprises software andhardware for wireless transmission of ultrasound images.
 14. The deviceas defined in claim 7, wherein the ultrasound image acquisition andprocessing unit is handheld.
 15. The device as defined in claim 7,wherein the ECG signal acquisition and processing unit comprises: amodule to extract certain features from the skin ECG signal a module togenerate a trigger based on certain features of the skin ECG signal 16.The device as defined in claim 7, wherein the ECG signal acquisition andprocessing unit comprises software and hardware for wirelesstransmission of ECG signals.
 17. The device as defined in claim 7,wherein the ECG signal acquisition and processing unit is handheld. 18.The device as defined in claim 7, wherein the display and graphical userinterface unit comprises: A graphical layout to simultaneously displayultrasound images and ECG signals at the tip of the vascular device; Agraphical user interface to allow for control and synchronization ofultrasound images and ECG signals.
 19. The device as defined in claim 7,wherein the display and graphical user interface unit comprises softwareto perform data decompression.
 20. The device as defined in claim 7,wherein the display and graphical user interface unit comprises softwareto perform pattern recognition.
 21. The device as defined in claim 7,wherein the display and graphical user interface unit comprises softwareto perform scan conversion.
 22. The device as defined in claim 7,wherein the display and graphical user interface unit comprises softwareto perform time gain compensation.
 23. The device as defined in claim 7,wherein the display and graphical user interface unit comprises softwareand hardware for wireless transmission of ultrasound images and ECGsignals.
 24. The device as defined in claim 7, wherein the display andgraphical user interface unit is handheld.